This book provides an analysis of group work in the teaching practicum in initial English teacher education. Focus lies mainly on issues related to team work, such as the relationships among team members and the specificities of this format of work. Field research was conducted at the School of Education of the University of São Paulo, in Brazil, and involved close observation of four groups of student teachers. This methodology allowed access to the “backstage” of the teaching practicum: the actors and actresses, what they think and do, how they prepare themselves and how they define their roles. Four implications of team teaching for the teaching practicum are highlighted: the choice of team partners, the organization of teams for lesson planning, joint instruction in the classroom and the emergence of informal leaders. The issue of informal leadership proved to be relevant in this study and represents an original contribution of this book to the field of teacher education.